CVE-2026-111749 — AIOHTTP: Cookie from subdomain can remove Host-Only Scope from existing cookies
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, Host-Only scope on an existing parent-domain cookie can be removed by a subdomai…
Published: 2026-10-19 · CVSS: 2.3 · CVSS 4.0
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, Host-Only scope on an existing parent-domain cookie can be removed by a subdomain. A user who accesses an untrusted subdomain can consequently have host-only protections stripped from cookies, although impact is limited when applications do not reflect those cookies to a browser. This issue is fixed in version 3.14.4.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7